机构树
    页面
       <el-form-item label="发生部门" prop="findDeptId">
              <!-- :show-all-levels="false"  显示全路径    separator="-"  分隔符  -->
              <!-- [props]  multiple : true,  多选
                 checkStrictly:true,   选择任意级别
                 emitPath :false , 不是数组

          -->
              <el-cascader v-model="form.findDeptId"
                :options="deptOptions"
                :props="{ expandTrigger: 'hover' ,  value: 'id'   ,emitPath:false , multiple : true,   }"
                
                clearable filterable placeholder="请选择部门">
                <template slot-scope="{ node, data }">
                  <span>{{ data.label }}</span>
                  <span v-if="!node.isLeaf"> ({{ data.children.length }}) </span>
                </template>
              </el-cascader>
            </el-form-item>
       数据

       import { treeselect  } from "@/api/system/dept";
       // 部门树选项
       deptOptions: undefined,

       /** 查询部门下拉树结构 */
       getTreeselect() {
         treeselect().then(response => {
           this.deptOptions = response.data;
         });
       },

        this.getTreeselect();
